<!DOCTYPE HTML>
<html>

<head>
<title>My WebSocket</title>
</head>

<body>
<input id="text" type="text" />
<button onclick="send()">Send</button>
<button onclick="close_websocket()">Close</button>
<div id="message"></div>
</body>

<script type="text/javascript">
var websocket = null;
//var ws_url = "ws://localhost:8080/notify/robot_001"
var uri = "/notify/robot_001"
var ws_url = "ws://" + window.location.host + uri;

//判断当前浏览器是否支持WebSocket
if('WebSocket' in window) {
  websocket = new WebSocket(ws_url);
} else {
  alert('Not support websocket')
}
//连接发生错误的回调方法
websocket.onerror = function() { setMessageInnerHTML("error"); };
//连接成功建立的回调方法
websocket.onopen = function(event) { setMessageInnerHTML("open"); }
//接收到消息的回调方法
websocket.onmessage = function(event) { setMessageInnerHTML(event.data); }
//连接关闭的回调方法
websocket.onclose = function() { setMessageInnerHTML("close"); }
//监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
window.onbeforeunload = function() { websocket.close(); }

//将消息显示在网页上
function setMessageInnerHTML(innerHTML) {
  document.getElementById('message').innerHTML += innerHTML + '<br/>';
}
//发送消息
function send() {
  var message = document.getElementById('text').value;
  websocket.send(message);
}

//关闭连接
function close_websocket() { websocket.close(); }
</script>

</html>